Sewing machine cutter

ABSTRACT

Sewing machine includes flat bed and cutting assembly includes mounting plate secured to machine with blade mounting arm integral with plate. Movable cutter blade is connected to arm and motivator between blade and mounting plate moves blade toward and away from flat bed of sewing machine. Stationary cutter blade is adjustably secured to flat bed of sewing machine and has cutting edge thereon arranged so that movable cutter blade sweeps across cutting edge of stationary blade when motivator is activated. Special mounts are provided for adjustably securing stationary cutter blade to bed of sewing machine so that stationary blade is adjustable for precise alignment of blade relative to movable blade.

United States Speer atent 1 v[73] Assignee: Spear Systems, Inc., Campbellsville,

[22] Filed: Jan. 17, 1972 [2]] Appl. No.: 218,148

[56] References Cited UNITED STATES PATENTS 2/1965 Weinkle 112/130 X 3,233,494 2/1966 Rupp 83/700 X 3,260,147 7/1966 Farabee 112/129 X FOREIGN PATENTS OR APPLICATIONS 134,372 11/1919 Great Britain 83/699 Primary Examiner-H. Hampton l-lunter Attorney, Agent, or Firm-C0nnolly and Hutz Sewing machine includes flat bed and cutting assembly includes mounting plate secured to machine with blade mounting arm integral with plate. Movable cutter blade is connected to arm and motivator between blade and mounting plate moves blade toward and away from flat bed of sewing machine. Stationary cutter blade is adjustably secured to flat bed of sewing machine and has cutting edge thereon arranged so that movable cutter blade sweeps across cutting edge of stationary blade when motivator is activated. Special mounts are provided for adjustably securing stationary cutter blade to bed of sewing machine so that stationary blade is adjustable for precise alignment of blade relative to movable blade.

4 Claims, 8 Drawing Figures 1 SEWING MACHINE CUTTER BACKGROUND OF THE INVENTION The present invention relates to a sewing machine and a cutting assembly that cooperates with the machine for severing material being worked upon by the machine.

As explained in applicants copending application Ser. No. 83,482, filed'Oct. 23, 1970, now U.S. Pat. No.

3,693,562, the cutting operation normally associated with sewing machine performance involves a manual operation carried out by the worker attending the ma- .chine. Alternatively, with many factory layouts an individual attendant performs the cutting operation on a series or line of sewing machines. The disadvantages of these manual procedures are obvious since manual cutting procedures involve more time than automatic or semi-automatic systems, and more important, the cutting operation is not always performed at the desired time.

. Moreover, with the implementation of .automatic or semi-automatic cutters, it is necessary that the cutting SUMMARY OF THE INVENTION Accordingly, the primary object of the present invention is to provide a sewing machine and a unique cutting assembly that cooperates with the machine for cutting material being worked upon by the machine operator, the cutting operation being achieved in a relatively simple but highly efficient manner over extended periods of use. I

In accordance with the present invention a sewing machine includes a flat bed and a cutting assembly includes a mounting plate secured to the sewing machine with a blade mounting arm integral with the mounting plate. A movable cutter blade is pivotally connected at its mid portion to the blade mounting arm for movement in a direction toward and away from the flat bed of the sewing machine. A motivator is connected between the movable cutter blade and the mounting plate for operating the blade toward and away from the flat bed of the sewing machine. A stationary cutter blade is adjustably secured to the flat bed of the sewing machine and it has a cutting edge thereon arranged so that the movable blade sweeps across the edge when the motivator is activated. Unique mounts are provided for adjustably securing the stationary cutter blade to the flatbed of the sewing machine and these mounts include at least one mounting element that extends through an enlarged aperture in the stationary cutter blade into the flat bed of the sewing machine. Adjustable st screws on the stationary cutter blade engage the mounting element at right angles thereto so that the position of the mounting element relative to the stationary blade is adjustable for precise alignment of the stationary blade relative to the movable blade.

Moreover, the motivator may comprise an air actuated cylinder connected to the movable blade at one side of the pivotal connection for urging that blade toward the flat bed of the sewing machine. A return spring connected to the movable blade at the other side of the pivotal connection urges the blade away'from the flat bed after the cutting operation when the motivator is deactivated.

Also, the mounts for the stationary cutter blade may include a pair of mounting elements and associated set screws positioned at one end of the stationary blade or alternatively, one mounting element at each end of the stationary cutter blade.

BRIEF DESCRIPTION OF THE DRAWING Novel features and advantages of the present invention in addition to those mentioned above will'become apparent from those skilled in the art from a reading of the following detailed description in conjunction with the accompany drawing wherein:

FIG. 1 is a rear elevational view of a sewing machine and a cutting assembly according to the present inven- 'tion;

FIG. 2 is an enlarged front elevational view of the stationary cutter blade shown in FIG. 1, according to the present invention;

. FIG. 3 is a top; plan view of the stationary cutter blade shown in FIG. 2;

FIG. 4 is a bottom plan view of the stationary cutter blade shown in FIG. 2;,

FIG. 5 is a left end elevational view of the stationary cutter blade shownin FIG. 2;

FIG. 6 is a right end elevational view of the stationary cutter blade shown in FIG. 2

FIG. 7 is a top plan view of another stationary cutter blade according to the present invention; and

FIG. 8 is a bottom plan view of the stationary cutter blade shown in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, a sewing machine 10 includes a flat bed 12 and the usual machine head 14. A cutting assembly 16 is associated with the sewing machine 10 for cutting threads, tape, bind ing, elastic, leather, and other types of material being worked upon by the sewing machine.

The cutting assembly 16 includes a mounting plate 18 secured to the sewing machine 10 by fasteners 20. A blade mounting arm 22 is integrally connected to the mounting plate 18 at 24. A movable cutter blade 26 having a cutting edge 28 is pivotally connected at its mid-portion to the blade mounting arm 22 for movement in a direction toward and away from the flat bed 12' of the sewing machine 10. The pivotal connection between the movable cutter blade 26 and the blade mounting arm 22 is identified by reference numeral 30.

A motivator in the form of an air cylinder 32 is connected between the movable cutter blade 26 at one end thereof and the mounting plate 18. The air cylinder unit 32 operates to move the movable cutter blade 26 in a direction toward and away from the flat bed 12 of the machine 10. The air cylinder unit includes a cylinder portion 34 connected to a tab 36 on the mounting plate 18 by a fastener 38. The air cylinder unit also includes a piston (not shown) inside the cylinder 34 and a piston rod 40 connected to the piston and the movable cutter blade by fastener 42. An air line 44 is connected to the cylinder 34 for driving the piston into the cylinder when air is delivered to the line. A coil spring 45 connected between the cutter blade 26 and the mounting plate 18 functions to return the blade to its starting position, as is clear from FIG. 1. The spring 45 is connected to the movable cutter blade at the side of the pivotal connection 30 opposite the side of the blade which is connected to the air cylinder unit 32.

The top cutting edge 28 of the movable cutter blade 26 cooperates with a stationary cutter blade 46 adjustably secured to the flat bed 12 of the sewing machine 10. As explained more fully below, the stationary cutter blade 46 is adjustably secured to the bed 12 of machine so that its cutting edge 48 is in alignment with the cutting edge 28 of blade 26 during the cutting operation. It is necessary that the stationary cutter blade 46 be precisely positioned so that the cutting edge 28 of blade 26 sweeps across edge 48 in scissor-like fashion when the air cylinder unit 32 is activated.

The stationary cutter blade 46 includes a recessed portion 50 at one end thereof, as best shown in FIGS. 3 and 5. A pair of enlarged apertures 52 are provided in the recess 50, and these openings extend through the cutter blade. A pair of mounting elements 54 loosely extend through the openings 52. The mounting elements may be machine screws having threaded portions the cross section of which is substantially less than the dimensions of the apertures 52. With this arrangement substantial movement of the mounting elements 54 in the openings 52 is possible. A pairof adjustable set screwsi56 having Allen wrench recesses 58 therein are associated with each mounting element 54 at right angles to the mounting element, as shown best in FIG. 3. The set screws extend through internally threaded bores in the stationary cutter 46.

The stationary cutter blade 46 is adjustably secured to the flat bed 12 of the sewing machine 10 in the following manner. First, the stationary blade 46 is approximately positioned on the flat bed 12 so that its cutting edge 48 is in alignment with the cutting edge 28 of the movablecutting blade 26. Internally threaded bores (not shown) are located in the flat bed 12 to receive the mounting elements 54 which extend through the openings 52 into the bores. The mounting elements are threaded into the bores in the bed 12 but not tightened. Next, the relative position of the stationary cutter blade on the bed 12 is adjusted by manipulating the set screws 56 until the cutting edge 48 of the blade is in precise alignment with the cutting edge.28 of the movable blade 26. Finally, the mounting elements 54 are tightened and the set screws are tightened to mount the stationary blade 46 to the bed 12.

FIGS. 7 and 8 illustrate an alternate embodiment60 ofa stationary cutter blade according to the present invention. The blade 60 is slightly different in appearance from the blade 46 in that the pair of mounting elements 54 are positioned one at each end of the blade. Otherwise, the stationary blade 60 is identical to the blade 46 and similar reference characters are utilized to identify similar parts. I

What is claimed is:

l. A sewing machine including a flatbed and a cutting assembly including a mounting plate secured to the sewing machine, a blade mounting arm integral with the mounting plate, a movable cutter blade pivotally connected at its mid-portion to the blade mounting arm for movement in a direction toward and away from the flatbed of the sewing machine, motivating means connected between the movable cutter blade and the mounting plate for moving the movable cutter blade toward and away from the flat bed of the sewing machine, a stationary cutter blade adjustably secured to the flat bed of the sewing machine, a cutting edge on the stationary cutter blade arranged so that the movable cutter blade sweeps across the cutting edge of the stationary blade when the motivating means is activated, and mounting means for adjustably securing the stationary cutter blade to the flat bed of the sewing machine including at least one element that extends through an enlarged aperture in the stationary cutter blade into the flat bed of the sewing machine, and adjustable set screws on the stationary cutter blade to en gaging the mounting element at right angles thereto whereby the position of the mounting element relative to the stationary cutter blade is adjustable for precise alignment-of the stationary blade relative to the movable blade.

2. A sewing machine and cutting assembly as in claim 1 wherein the motivating means comprises an air actuated cylinder connected to the movable cutter blade at one side of the pivotal connection for urging the movable cutter blade toward the flat bed of the sewing machine, and a return spring connected to the movable cutter blade at the other side of the pivotal connection for urging the movable cutter blade away from the flat bed of the sewing machine after the cutting operation.

3. A cutter blade assembly for a sewing machine having a flat bed, the assembly comprising a stationary cutter blade having a cutting edge and a mounting aperture, a mounting element extending through the mounting aperture for securing the cutter blade to the flat bed of the sewing machine, the mounting element having a cross section substantially less than the dimensions of the aperture through which it extends, and adjustable set screws on the stationary cutter blade to engaging the mounting element at right angles thereto wherebythe position of the mounting element relative to the stationary cutter blade is adjustable for precisely locating the cutter blade on the flat bed of the sewing machine.

4. A cutter blade assembly as in claim 3 including a second mounting aperture in the stationary cutter blade and a second mounting element for securing the stationary blade tothe flat bed of the sewing machine, and adjustable set screws in the stationary cutter blade associated with the second mounting element for adjusting the position of the cutter blade relative to the mounting elements and the flat bed of the sewing machine. 

1. A sewing machine including a flat bed and a cutting assembly including a mounting plate secured to the sewing machine, a blade mounting arm integral with the mounting plate, a movable cutter blade pivotally connected at its mid-portion to the blade mounting arm for movement in a direction toward and away from the flat bed of the sewing machine, motivating means connected between the movable cutter blade and the mounting plate for moving the movable cutter blade toward and away from the flat bed of the sewing machine, a stationary cutter blade adjustably secured to the flat bed of the sewing machine, a cutting edge on the stationary cutter blade arranged so that the movable cutter blade sweeps across the cutting edge of the stationary blade when the motivating means is activated, and mounting means for adjustably securing the stationary cutter blade to the flat bed of the sewing machine including at least one element that extends through an enlarged aperture in the stationary cutter blade into the flat bed of the sewing machine, and adjustable set screws on the stationary cutter blade to engaging the mounting element at right angles thereto whereby the position of the mounting element relative to the stationary cutter blade is adjustable for precise alignment of the stationary blade relative to the movable blade.
 2. A sewing machine And cutting assembly as in claim 1 wherein the motivating means comprises an air actuated cylinder connected to the movable cutter blade at one side of the pivotal connection for urging the movable cutter blade toward the flat bed of the sewing machine, and a return spring connected to the movable cutter blade at the other side of the pivotal connection for urging the movable cutter blade away from the flat bed of the sewing machine after the cutting operation.
 3. A cutter blade assembly for a sewing machine having a flat bed, the assembly comprising a stationary cutter blade having a cutting edge and a mounting aperture, a mounting element extending through the mounting aperture for securing the cutter blade to the flat bed of the sewing machine, the mounting element having a cross section substantially less than the dimensions of the aperture through which it extends, and adjustable set screws on the stationary cutter blade to engaging the mounting element at right angles thereto whereby the position of the mounting element relative to the stationary cutter blade is adjustable for precisely locating the cutter blade on the flat bed of the sewing machine.
 4. A cutter blade assembly as in claim 3 including a second mounting aperture in the stationary cutter blade and a second mounting element for securing the stationary blade to the flat bed of the sewing machine, and adjustable set screws in the stationary cutter blade associated with the second mounting element for adjusting the position of the cutter blade relative to the mounting elements and the flat bed of the sewing machine. 